1. Field of the Invention
The present invention generally relates to a substrate attachment structure. More specifically, the prevent invention relates to a substrate attachment structure for attaching a substrate to a chassis.
2. Background Information
With a conventional substrate attachment structure, a substrate is attached to a chassis. Threaded holes for attachment screws are formed at two locations in the chassis. Screw insertion holes are formed at two locations in the substrate. When the attachment screws are fastened, the substrate is positioned overlapping the chassis, and the two screw insertion holes in the substrate are lined up with the two threaded holes in the chassis. Then, the attachment screws are inserted into the screw insertion holes and threaded into the threaded holes to fasten the substrate and the chassis together. With the conventional substrate attachment structure, two screw fastening locations are used to ensure necessary attachment strength and prevent the substrate from lifting up from the chassis. Therefore, if the substrate is large in size, then more than two locations need to be screwed down to ensure the necessary attachment strength.
With the conventional substrate attachment structure, after the substrate is positioned on the chassis and the screw insertion holes and threaded holes were lined up, the necessary number of the attachment screws has to be threaded in and tightened. Thus, positioning the substrate requires skill. Furthermore, fastening with attachment screws at two or more separate locations according to the size of the substrate is necessary to ensure the necessary attachment strength. As the number of screw fastening locations increased, the number of the screw fastening job also increased. Thus, the screw fastening job becomes complicated, which increases the manufacturing cost.
Meanwhile, with another conventional substrate attachment structure, a substrate is attached to a sheet metal without the use of attachment screws (see Japanese Laid-Open Utility Model Application H2-20384, for example). With the substrate attachment structure, the substrate is hooked at two places on left and right sides to receivers of the sheet metal. An elastic latching protrusion is provided to a distal end of a lead clamper. The elastic latching protrusion is inserted in and latched to holes provided to both the substrate and the sheet metal. The lead damper is utilized to support a lead wire.
The conventional substrate attachment structure fixes the substrate by hooking the substrate to the receivers of the sheet metal. With the conventional substrate attachment structure, an edge of the substrate is hooked to the receivers of the sheet metal. Furthermore, the lead damper is provided near an end of the substrate on the opposite side of the edge of the substrate.
However, depending on the type of electrical circuit formed on the substrate, it is conceivable that hooking the receivers to the edge of the substrate is unsuitable or even impossible. For instance, when electrical or electronic parts are mounted at the edge of the substrate, or when an electrical circuit pattern is formed at the edge of the substrate, the electrical or electronic parts get in the way of hooking the receivers, or the receivers short out an electrical path of the circuit.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved substrate attachment structure. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.